1. Field of the Invention
The invention relates generally to techniques for protecting electronic circuits from damage due to cable discharge. More particularly, it relates to apparatus and methods for safely terminating electronic cables and/or providing points of entry to electronic circuits.
2. Description of the Prior Art
Cable discharge can be a serious problem for installers of electronic systems. Cable discharge generally results from an electrical phenomenon wherein cables in an electrical system build up large and potentially damaging electric charges, not unlike static electricity. These stored charges are often the result of processes that are currently not well understood in the art. Consequently, when an installer connects a piece of electronic equipment to a system cable, that cable could hold an unforeseen electric charge, and that charge could readily dissipate into that piece of equipment. Thus, when an installer initially connects an electronic component to a system cable, the component can unexpectedly receive a large, destructive discharge of electricity.
Telecommunications, data communications and electronic networking systems, which are particularly susceptible to damage from cable discharge, employ various kinds of connector circuits for cabling equipment together. For example, a modular connector, i.e., a modular jack along with its corresponding modular plug, is one well-known type of connector that has found widespread use in many communication and networking systems. Modular connectors are easy to use. Users can couple and uncouple most connectors without tools and with little manual effort. In addition, modular connectors are generally durable, reliable, and inexpensive to manufacture and install.
A typical modular jack, a female connector, comprises multiple electrical conductors contained within a cavity of a molded plastic body. The jack conductors act as electrical contacts, which mate with corresponding contacts on a modular plug, a male connector that inserts into a jack cavity. A modular plug normally terminates a cable segment. A modular jack, which may also terminate a cable segment, primarily mounts on a rigid support, e.g., a printed circuit board (PCB), a chassis of an electronic apparatus, or a cable termination device located in a telecommunications closet.
Conventional modular connectors include four-wire RJ-11, six-wire RJ-12 and eight-wire RJ-45 connectors. A variety of telecommunication, data communication and networking equipment contain RJ-45 connectors. For instance, conventional LAN (local area network) systems, such as Ethernet systems, often use RJ-45 connectors to make cable connections between computers and other LAN devices dispersed over an area, such as an office building.
Although most cable connectors, including modular connectors, have served the purpose in the past, installers of electronic equipment still encounter cable discharge problems. Thus, there is a need in the art for techniques to overcome problems related to cable discharge.
The present invention satisfies this need in the art by providing apparatus and methods for safely terminating electronic cables and/or providing points of entry to electronic circuits. One aspect of the invention comprises a connector assembly that prevents damage caused by cable discharge when a system cable connects to an electronic circuit having a source of ground potential. The connector assembly comprises first and second connectors, each having a plurality of contacts, and a device for mating the connectors such that corresponding contacts connect to each other. A grounding device briefly connects all of the contacts to the ground potential when the connectors initially or partially mate, and removes the contacts from the ground potential when the connectors fully mate.
Another aspect of the invention involves a connector assembly comprising a first connector having a plurality of rigid contacts and a second connector having a plurality of resilient contacts. The connector also includes apparatus for mating the first and second connectors such that each of the rigid contacts connect to and flex a different one of the resilient contacts when the connectors mate. A ground device grounds the resilient contacts when the connectors are unmated, grounds the resilient and rigid contacts when the connectors are partially mated, and disconnects the resilient and rigid contacts from ground when the connectors are fully mated.
In addition, the second connector includes a body having a cavity with an access opening. The resilient contacts mount in the cavity, and a grounding conductor mounts on the body in contact with the resilient contacts. The first connector includes a plug shaped to fit within the cavity when the first and second connectors mate.
One embodiment of the invention includes an electromagnetic shield that covers the body and connects the grounding conductor to a ground potential. In another embodiment, the ground device includes a plurality of grounding conductors, each connected to a different one of the resilient contacts and disconnects from the rigid contacts when the connectors are unmated. The grounding contacts connect to a different one of the contacts when the connectors partially mate, and disconnect from the contacts when the connectors fully mate. In addition, the connector assembly functions as an eight-contact, RJ-45 connector, and the first connector is a modular plug while the second connector is a modular jack.
A further aspect of the invention comprises a method of connecting a cable terminated in a first set of contacts to an electronic circuit having a second set of contacts and a ground potential. The method comprises the steps of: connecting the second set of contacts to the ground potential; connecting the first set of contacts to the second set of contacts while the second set of contacts remain connected to the ground potential; and disconnecting the first and second sets of contacts from the ground potential while the first set of contacts remain connected to the second set of contacts.